What is the Pareto Principle AKA the 80/20 rule?

The Pareto Principle, also known as the 80/20 rule, states that roughly 80% of the effects come from 20% of the causes. It is a principle named after Italian economist Vilfredo Pareto, who observed that approximately 80% of the land in Italy was owned by 20% of the population. This principle has been applied to various fields and phenomena, suggesting that a small portion of inputs or efforts often leads to a majority of the outcomes or results. It is a concept used to analyze and prioritize resources, tasks, and efforts for maximum efficiency and impact.